<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			*{
				margin: 0;
				padding: 0;
			}
			div{
				width: 100px;
				height: 50px;
				background: #ccc;
				margin: 0 auto;
				margin-top: 20px;
				text-align: center;
				line-height: 50px;
				position: absolute;
				/* left: 50%;
				margin-left: -150px; */
				/* position: relative;*/
			}
			/* div img{
				width: 20px;
				position: absolute;
				top:-18px;
				left: 50%;
				margin-left: -10px;
			} */
		</style>
	</head>
	<body>
		<!-- 
			如何让绝对定位的元素水平居中
			
			1只需要设置绝对定位元素的left: 50%;
			
			2再设置margin-left: -宽度的一半;
		 -->
		 <div>
			 导航地图
			 <!-- <img src="img/pointer.png" alt=""> -->
		</div>
	</body>
</html>
